The MRI apparatus is an imaging diagnostic apparatus which magnetically excites nuclear spins of an object set in a static magnetic field with RF (radio frequency) signals having the Larmor frequency and reconstructs an image based on MR (magnetic resonance) signals generated due to the excitation.
In the MRI apparatus, the gradient coil to apply gradient magnetic fields to an imaging area produces heat during an operation. Accordingly, a pipe of cooling water is provided spirally next to the main coil, which composes the gradient coil, and the gradient coil is cooled by the circulation of the cooling water.